1. Field of the Invention
This invention relates to reactive pyridone azo dyestuffs, and more specifically it relates to reactive pyridone monoazo and disazo dyestuffs containing a specific reactive group and a specific disperse group in the molecular structure.
2. Description of the Prior Art
Heretofore, reactive dyestuffs etc. have been employed for dyeing natural fibers such as cotton etc. while disperse dyestuffs have mainly been used for dyeing polyester fibers etc.
Recently, there has been an increased demand for mixed fibers comprising natural fibers such as cotton etc. and synthetic fibers such as polyester etc., and in order to dye such mixed fibers with a single dyestuff and even by a single dyeing step, reactive disperse dyestuffs were proposed. Especially, a reactive pyridone monoazo dyestuff having the following structure was proposed as a reactive disperse dyestuff which can dye mixed fibers in a yellow color having washing fastness (Japanese Patent Application Laid-open No. 151064/1980, DE No. 2918881 and EPC No. 19728). ##STR5## However, its light fastness was not adequate, and thus further improvement has been sought.